For hydrocarbon polluted soils that underwent bioremediation it is important to assess its condition after a period of time, but it is more useful when there is an opportunity of comparison against an unpolluted soil ...For hydrocarbon polluted soils that underwent bioremediation it is important to assess its condition after a period of time, but it is more useful when there is an opportunity of comparison against an unpolluted soil and an untreated polluted one. This paper provides a comparison of three adjacent parcels, being the first clean, the second polluted and bioremediated, the third polluted and left to natural attenuation. Study was conducted determining pH, electrical conductivity, carbonates, soil organic matter, chemical oxygen demand, eight anions, and twelve metals. Data were compared against those references for agricultural soils found in the Mexican NOM-021. A Pearson correlation was applied to find coincidences between the three parcels, obtained results allowed to say that bioremediated parcel allowed for most uniform pH, negligible salinity risk, and medium content of soil organic matter, but treatment has enabled heavy metal accumulation since its values are higher in respect to the other parcels. Natural attenuated parcel has some spots with lower pH, a moderately saline risk, a high content of soil organic matter, and lower content of heavy metals. The clean or unaffected parcel exhibit the higher pH values, a slightly saline condition, soil organic matter ranges from high to very high content, heavy metals content is medium, but no reaching dangerous levels. An important assessment is that bioremediation has enhanced the bioavailability of soil organic matter but it is not similar to the values in the unpolluted parcel.展开更多
The toxicity of several insecticides to first and fourth instar larvae in the laboratory,and the control effect of the nine insecticides to the fourth instar larvae of Bradysia odoriphaga Yang et Zhang in pots wer...The toxicity of several insecticides to first and fourth instar larvae in the laboratory,and the control effect of the nine insecticides to the fourth instar larvae of Bradysia odoriphaga Yang et Zhang in pots were tested respectively.The results demonstrated that chlorfluazuron,chlorpyrifos,phoxim and triazophos not only showed the higher toxicity in the laboratory,but also had good control efficiency in pots.The acting speed of chlorfluazuron was slow,and fourth instar larvae treated by it became deformed pupa when they pupated.Chinese chive maggot was not sensitive to cyromazine.Chlorfluazuron,chlorpyrifos,phoxim and triazophos had high efficiency to control Chinese chive maggot and low poisonous,so they can be applied in course of producing unpolluting vegetable.展开更多
文摘For hydrocarbon polluted soils that underwent bioremediation it is important to assess its condition after a period of time, but it is more useful when there is an opportunity of comparison against an unpolluted soil and an untreated polluted one. This paper provides a comparison of three adjacent parcels, being the first clean, the second polluted and bioremediated, the third polluted and left to natural attenuation. Study was conducted determining pH, electrical conductivity, carbonates, soil organic matter, chemical oxygen demand, eight anions, and twelve metals. Data were compared against those references for agricultural soils found in the Mexican NOM-021. A Pearson correlation was applied to find coincidences between the three parcels, obtained results allowed to say that bioremediated parcel allowed for most uniform pH, negligible salinity risk, and medium content of soil organic matter, but treatment has enabled heavy metal accumulation since its values are higher in respect to the other parcels. Natural attenuated parcel has some spots with lower pH, a moderately saline risk, a high content of soil organic matter, and lower content of heavy metals. The clean or unaffected parcel exhibit the higher pH values, a slightly saline condition, soil organic matter ranges from high to very high content, heavy metals content is medium, but no reaching dangerous levels. An important assessment is that bioremediation has enhanced the bioavailability of soil organic matter but it is not similar to the values in the unpolluted parcel.
文摘The toxicity of several insecticides to first and fourth instar larvae in the laboratory,and the control effect of the nine insecticides to the fourth instar larvae of Bradysia odoriphaga Yang et Zhang in pots were tested respectively.The results demonstrated that chlorfluazuron,chlorpyrifos,phoxim and triazophos not only showed the higher toxicity in the laboratory,but also had good control efficiency in pots.The acting speed of chlorfluazuron was slow,and fourth instar larvae treated by it became deformed pupa when they pupated.Chinese chive maggot was not sensitive to cyromazine.Chlorfluazuron,chlorpyrifos,phoxim and triazophos had high efficiency to control Chinese chive maggot and low poisonous,so they can be applied in course of producing unpolluting vegetable.
